Date of Award
At the Los Alamos National Laboratory (LANL), low level nuclear waste (LLW) is processed for disposal at the Waste Isolation Pilot Plant. This waste is processed in a glovebox and then placed into a 55 gallon drum and sent to a nondestructive assay (NDA) laboratory to determine if the waste within the drum's reactivity is below 100nCi/g stipulated by the regulation held by the Enviromental Protection Agency (EPA). In several cases every year, the reactivity of the drum is exceeded, thus requiring a costly and dangerous procedural deviation to divide the contents of the drum to reach an acceptable level of radioactivity. To avoid this problem, an in-line waste assay system must be developed to measure specifically plutonium-240 but also must give a possibility of measuring other types of radioactive materials such as Uranium-235. This product must have the ability to be applied to gloveboxes globally. This will require that the device has the capability of assaying a fully loaded 55-gallon drum that is inserted into the glovebox through a penetration in the floor of the glovebox before movement to the NDA laboratory. This assay must be completed within an hour, while maintaining an ergonomically efficient design. To satisfy these requirements, the goal was to take a neutron counting system available on the market and develop a mechanized collar to hold these devices while it assays the drum's waste underneath the glovebox.
The neutron counter that will be applied to the design is Canberra Industries' model JCC-71,72, and 73  accompanied with the JR-14 shift register  and neutron counting software . The main aspect of the design will be the development of a mechanized collar operating underneath the glovebox around the floor penetration to safely assay the waste in 2-3 sections on the drum. This will require the collar to have a vertical drive mechanism, a controls component and the construction of a holding rack for the counting slabs. The design will accompany the 6 He-3 slabs fashioned around the drum with one of the holding positions having the ability to accompany a passive or active slab depending on the application desired. The design will include a minimal amount of areas with hard to clean spaces. This design will accomplish all of the specifications explained above and hope to make the operations at nuclear processing facilities more efficient.
Elloso, Andrew; Murphy, Ryan; Simpson, Robert; and Sullivan, Thomas, "LANL Plutonium Assessment" (2017). Mechanical Engineering Capstone Design Projects. Paper 9.